ON THE ERRATIC BLOCKS OF ENGLAND, IRELAND, AND WALES. 243 



the series, bear a strong family resemblance to those from other parts, and 

 so are no guide to ice movements during Glacial times. 



There is, however, one rock which is an exception to this, and which 

 gives a good starting-point followed by an excellent tx-ail to the boulder 

 hunter. This is a conglomerate which is to be found at the base of the Car- 

 boniferous limestone at Malham Tarn, and at Noi-ber, near Clapbam, York- 

 shire. The conglomerate consists of a fine gravel of Silurian shale, the 

 pebbles being compacted in a matrix of limestone. The former are of a 

 greenish grey, the latter is of a creamy brown colour. When the rock is 

 broken the fracture is a very clean one, passing through pebbles and 

 matrix alike, and then to a casual observer it looks like a light mottled 

 limestone. Where it has been subjected to the solvent action of weather- 

 ing the pebbles stand out from the rock, giving well-marked oblong forms 

 of which the surfaces are well preserved. 



Conglomerate of this type occurs in a band across Malham Tarn, and 

 showing best on its eastern margin, and also on the southern face of Nor- 

 ber, one mile E.N.E. of Clapham, a hill well known to geologists for its 

 splendid train of Silurian boulders resting on the limestone. The con- 

 glomerate is no less interesting. It contains, besides the fine gravel, 

 large boulders up to half a ton in weight, and interspersed with the 

 gravel are coi'als, probably of the age of its deposition. Detached 

 boulders of this rock range over a distance so far as I have seen them of 

 25 miles. 



The nearest specimens worthy of note are a large boulder in the fields, 

 J mile S.E. of the Methodist Chapel iu Malham — pointed out to me by 

 Mr. Walter Morrison, M.P., and others, which he tells me were to be seen 

 formerly along the road by the school on Kirkby Top. Some occur in 

 walls a little to the east, between the first locality and Goredale Beck. 

 These are mostly small. 



A large boulder with quite a bed of loose gravel beneath it produced 

 by its disintegration lies on the i-ight branch of a stream running down 

 south from the upper road between Malham and Settle on the moor 

 about 200 yards from the road. This is more out of a north and south line 

 from Malham Tarn than any of the others ; which fact suggests that it 

 may have come from Norber, but on the whole it is more likely from the 

 Tarn, which lies N. 30° E., the nearest point of origin. Two other bould- 

 ers appear to have been transported into Ingle Beck, south of the lane 

 leading from Airton towards Holmes Gill Green, and have been built 

 into walls there. These lie about S. 15° W. from the Tarn. 



Beyond this point the boulders as we get further from the source are 

 fewer and more scattered. Two more examples only have I seen, but 

 these are remarkable. One was found in the banks of Pendle Water 

 below the Old Hall at Roughlee — famous as the residence of Mistress 

 Nutter as mentioned in ' Ainsworth's Lancashire Witches.' 



This was a glaciated boulder of the conglomerate, about 14" long, of 

 oval form, and lay at about 600 ft. elevation. Scratches on Twiston Moor 

 to the north pointing in this direction, and also in a straight line nearly 

 for Norber, lie at an elevation of about 1,100 ft. ; and if the boulder came 

 from Norber it must have overridden this ridge, a continuation of the 

 Pendle range, and crossed over ground 500 ft. higher and 150 ft. lower 

 than its present site. 



On the other hand, if from Malham Tarn it may have been carried 

 south by the ice, along the Aire valley, to Bell Bush, and thence across 



